THE CHALLENGE

95% of all hydrogen produced globally is derived from fossil fuel sources with the balance produced from renewable sources including the electrolysis of water.

This is due to sustainable/renewable methods being by order of magnitude, more expensive. Modern water electrolysis technologies rely on the use of membranes or diaphragms to provide a means of separating the produced constituent gases. Issues pertaining to reliability, operating parameter thresholds and expensive materials of construction due to the inclusion of membranes/diaphragms impedes the absorption of these technologies into industry. DEFTTM alkaline electrolysis does not utilise conventional diaphragms and membranes, and hence provides significant potential to generate a low CAPEX and OPEX design.

DEFT™ solution

The Divergent-Electrode-Flow-Through (DEFTTM) solution incorporates some key advantages from both alkaline and PEM systems. DEFTTM manipulates the flow of electrolyte through porous electrodes in order to obtain separation of produced hydrogen and oxygen gases. By controlling where gas is formed on the electrode surface through insulation, low parasitic loads for pumping are attained making the technology equivalently efficient to conventional water electrolysis methods, with the difference of making use of fewer components and unimpeded operating parameters. The goal for Hydrox Holdings is to realise the commercialisation of its membraneless alkaline water electrolysis technologies and to continue working towards improving and developing clean energy technologies for the future.

Intermediate Temperature DEFT™ solution

DEFTTM is designed to push the conventional operating thresholds of electrolysis technologies as it does not utilize conventional diaphragms/membranes. Due to this the huge benefits associated with medium-temperature electrolysis can now be realized. An energy efficiency of 95%, coupled with a 10-fold increase in current density at the higher temperatures have been achieved by scientists from various universities but all their tests had to be abandoned due to membrane failures. In standard temperature electrolysis, 40% of the total energy provided to the stack is lost as waste heat whilst in Intermediate Temperature Electrolysis (ITE), (200 – 300 oC), the waste heat would be utilised to enhance the stack efficiency.

The benefits of operating at higher temperatures are:
– Thermodynamic gains, as the electrical energy required to split water molecules decreases with increased temperature. The reaction consumes more heat and less electricity. There is a 3.5 times better conductivity at 250 oC compared to the normal operating temperature of 80 oC.
– Reaction kinetics are much faster as both the hydrogen and oxygen evolution reactions (HER and OER) increase by order of magnitude with higher hydrogen and oxygen production rates. Hydrogen can now be produced at much higher power densities and at lower potential.
– Reduction in electrolytic resistance with a huge increase in ionic transport conduction.

AAE solution

Advanced Alkaline Electrolyser (AAE) technology is competitive with current alkaline electrolysis and can achieve efficiencies up to 70% HHV at production costs < 3 $/kg H2 at large forecourt scales. Hydrox Holding’s modular AAE solution makes use of conventional alkaline electrolysis principles, coupled with Hydrox’s vast knowledge-base and supplier & industrial network to provide an electrolysis unit tailor-made to address both the local and African hydrogen market. This is significant as it will establish Hydrox Holdings as the first OEM of liquid alkaline electrolysers in Africa with the ability to provide “GREEN” electrolytic hydrogen solutions and fully exploit the fast-growing hydrogen economy.

The Hydrogen economy